相关论文: Gravitational Leptogenesis in Bounce Cosmology
We study a scenario in which the baryon asymmetry of the universe arises from a cosmological phase transition where lepton-number is spontaneously broken. If the phase transition is first order, a lepton-number asymmetry can arise at the…
In this talk we present a mechanism for leptogenesis which is based on gravity waves produced during inflation. We show that when inflation is driven by a pseudo-scalar field the metric perturbations generated during inflation can become…
In a previous work, a mechanism was presented by which baryon asymmetry can be generated during inflation from elliptically polarized gravitons. Nonetheless, the mechanism only generated a realistic baryon asymmetry under special…
Partially chiral stochastic gravitational wave backgrounds can arise from various processes in the early Universe. The gravitational ABJ anomaly links the chirality of the gravitational field to the chiral fermions, resulting in the…
The origin of matter-antimatter asymmetry is one of the most important outstanding problems at the interface of particle physics and cosmology. Gravitational leptogenesis (baryogenesis) provides a possible mechanism through explicit…
We study gravitational wave production during Abelian gauge-field preheating following inflation. We consider both scalar and pseudoscalar inflaton models coupled directly to Abelian gauge fields via either a dilatonic coupling to the…
Leptogenesis is arguably the best motivated theory of baryogenesis given the discovery of finite neutrino masses, yet its experimental test is elusive given its high energy scale. We discuss gravitational waves (GWs) produced via graviton…
We show that gravitational leptogenesis with dynamical $CPT$ breaking in an expanding universe can be reconciled with the exponential $f(R)$ gravity model, which introduces only one additional parameter $\beta$ compared to the standard…
We examine the generation of baryon asymmetry at the weak scale from a primordial lepton asymmetry. If the electroweak phase transition is first order, partial reflection of tau leptons off the bubble walls and the resulting hypercharge…
The problem of cosmological graviton creation for homogeneous and isotropic universes with elliptical ($\vae =+1$) and hyperbolical ($\vae =-1$) geometries is addressed. The gravitational wave equation is established for a self-gravitating…
The role of the auxiliary scalar field $\phi$ of Brans-Dicke theory played in baryon number asymmetry is discussed in this paper. We consider a derivative coupling of this gravitational scalar field to the baryon current ${J^{\mu}}_B$ or…
We review the experimental evidence for a net baryon density in cosmology, and the theoretical mechanism for producing it, called leptogenesis, which relies on the creation of a lepton asymmetry at an intermediate step. The naturality of…
Successful soft leptogenesis requires small B-terms for the right-handed sneutrinos and a large CP violating phase between the A- and B-terms. We show that this situation is realized naturally within the framework of gauge mediated…
We introduce a dimension five CP violating coupling between the Ricci scalar and fermions. This operator splits the energy level between neutrinos and anti-neutrinos and can generate a lepton-asymmetry in the the radiation era if heavy…
Low-scale leptogenesis provides an economic and testable description of the origin of the baryon asymmetry of the Universe. In this scenario, the baryon asymmetry of the Universe is reprocessed from the lepton asymmetry by electroweak…
We examine the impact of charged lepton Yukawa equilibration on leptogenesis during gravitational reheating. During the post-inflationary era, the inflaton field is assumed to oscillate around the minimum of a monomial potential, leading to…
We study the scale at which one can generate the lepton asymmetry of the universe which could then get converted to a baryon asymmetry during the electroweak phase transition. We consider the possibility that the Yukawa couplings are small…
We point out that the so-called ``soft leptogenesis'' can occur at TeV scale if the $B$ term is generated through radiative corrections which involve two-loop diagrams with the gaugino exchange. This mechasnism requires the non-trivial CP…
We study the possibility of generating the observed baryon asymmetry via leptogenesis in the decay of heavy Standard Model singlet fermions which carry lepton number, in a framework without Majorana masses above the electroweak scale. Such…
In this article, we discuss the mechanism for generating the lepton/baryon number and its subsequent conservation based on extradimensional evolution. The internal angular momentum of extra space is related to the lepton/baryon charge.…